1. Field
Apparatuses and methods consistent with exemplary embodiments relate to a spatial light modulator, and more particularly, to a spatial light modulator that is manufactured in a very small size and includes an electrode that has a nano-antenna structure, and a display apparatus including the spatial light modulator.
2. Description of Related Art
Modulation is used to alter one or more properties of a transmission signal. A spatial light modulator may be used to transmit or block incident light, control the intensity or the phase of light, and the like, which passes through the spatial light modulator. As an example, a spatial light modulator may be variously manufactured as a semiconductor-based spatial light modulator using an electro-absorption effect, a spatial light modulator using liquid crystal, and the like.
Generally, a spatial light modulator has a liquid crystal design that includes a plurality of pixels having a structure in which a liquid crystal is disposed between two electrodes. When an electric field is generated in the liquid crystal by applying a voltage to the two electrodes in each pixel, an orientation of liquid-crystal molecules changes along a direction of the electric field. As a result, a phase and a polarization direction of light proceeding from the liquid crystal change according to the orientation of liquid-crystal molecules. As an example, a liquid crystal spatial light modulator may be included in a liquid crystal display apparatus, a holographic display apparatus, a polarization rotator, a phase retarder, and the like.
However, in a liquid crystal spatial light modulator, a liquid crystal cell generally requires a thickness of several micrometers (um) in order to obtain an optical path that is sufficient enough to change a phase of light inside a liquid crystal. Because of this required thickness, a size of the electrodes must be large enough to provide a sufficient electric field for the liquid crystal cell.
Accordingly, it is difficult to reduce the size of pixels to prevent interference of electric fields between adjacent pixels. For example, a pixel pitch of the liquid crystal spatial light modulator may be equal to or higher than several um. Currently, studies for reducing the sizes of pixels of a spatial light modulator are being performed in an effort to produce a high-resolution holographic display apparatus.